*Addendum* - The "tactile buzzer" is just the battery. Brain fart, not sure where my mind was when writing that out. Whoops! 😅 - Some folks were curious how the middle gap between the layers is made. I don't know for sure, but it's likely that they used a sacrificial silicon dioxide* (SiO2 aka glass) layer in between the two "functional" layers. So the process flow would have been: pattern and etch bottom layer's array of holes, deposit a thick layer of SiO2, deposit and pattern subsequent polysilicon layers (doped or undoped), then finally etch out the SiO2 layer with HF or plasma. Then flip over and DRIE etch the big cavity from the backside. That is also likely why the dimples are dimple-shaped... they are just following the curve of the sacrificial layer that was filling the holes from the very first layer. *I suspect SiO2 because there was some EDS data (not shown in the video) which showed high concentrations of SiO2 right at the broken edge between the layers, where they meet at the "bulk" of the substrate. I think that's leftover from the sacrificial etch process.

@98f5

6 ай бұрын

And here i was googling wtf a tactile buzzer is lol

@98f5

6 ай бұрын

Your work continues to blow my mind also. Thank you for bringing this high quality educational entertainment to me. 😊😊

@jupa7166

6 ай бұрын

I didn't catch it - I was too busy looking at that mems marvel (:

@eSKAone-

6 ай бұрын

It's interesting we see no microorganisms. It's really work to keep things sterile.

@jonslg240

6 ай бұрын

So did the rapper MIMS name himself after MEMS, or did MEMS get backronym'd from MIMS? Or is it just a coincidence? Either way 🤯 mind blown! 😂😂

Honestly I might be most impressed by the fact that you made a 3d model of the microphone for a mere couple seconds of footage!

@DaveNagy1

6 ай бұрын

Yeah, that was a really impressive render! Was that model hand made, or is there some way to automagically process SEM images into 3D models?

@novaenricarter705

6 ай бұрын

@@DaveNagy1 I believe it was hand made as it looked different in many ways

@mu9600

6 ай бұрын

making conceptual basic 3d models is not that hard if someone has a good sense of 3d imagination. i find it crazier that he is able to break a thing many times smaller than a hair in two 🤯

@mwarnas

6 ай бұрын

And all that for ten bucks

@zyeborm

6 ай бұрын

​@@DaveNagy1for sure hand made. The model itself would be pretty quick to make, but texturing, creating the environment, animating all that would take a decent amount of time. I'd imagine this would probably be something he modelled then sent out to an animator to render up. There's not a lot of cross over between cad modelling for engineering and pretty stuff sadly. That said I wouldn't put it past him to do it all himself, legend.

The fact that this sort of tech is $10 for a whole system is literally marvelous. 30 years ago this would be actual magic.

@jimurrata6785

6 ай бұрын

Crazy. I just made much the same comment before seeing yours. It really is amazing how fast microelectronics has developed

@Flumphinator

6 ай бұрын

@@jimurrata6785 I absolutely cannot wait to see what’s coming in another 30 years.

@GeraltOfRivia69

6 ай бұрын

Magic is technology not yet discovered

@pharaohsmagician8329

6 ай бұрын

​@@GeraltOfRivia69exactly! Everything is possible

@Jose04537

6 ай бұрын

"Any sufficiently advanced technology is indistinguishable from magic" Arthur C. Clarke

Your video making skills are off the hook. I love the CGI of the microphone and all the beautiful imagery. Your hard work to make these videos is super appreciated.

@BraxtonHoward

6 ай бұрын

The rendered footage was some of the best I've seen before on educational content.

@SomeSortaPro

6 ай бұрын

I am in awe, I have gotten into microelectronics lately after watching lots of Asianometry videos and this visual exploration of this microphone was astonishing. Seeing the small features contrasted with a human hair really put everything in perspective in a wonderful way.

@andrew2004sydney

6 ай бұрын

Awesome video!

"Buddy I can't hear ya, think you forgot your microphone in the electron microscope again"

@linecraftman3907

6 ай бұрын

Sounds like vacuum in there!

@klab3929

6 ай бұрын

@@linecraftman3907 sounds like space!

It's perhaps not that surprising that you could create a capacitive microsphone from silicon, but what's mind-blowing to me is that it's such a good microphone. It doesn't seem obvious that you would be able to make a microphone that could do anything other than simply detect the presence of sound. Insane engineering to get to a useful microphone

@drkastenbrot

6 ай бұрын

key to it all is the perfect repeatability and precision of silicon lithography. the signal is very weak and the frequency response is terrible but it can be precisely characterised and corrected using the built in integrated circuit.

@mattsains

6 ай бұрын

@@drkastenbrot cool

@revimfadli4666

6 ай бұрын

​@@drkastenbrotalso the ability to make an ic with that capability fit in there with such low power

@tookitogo

6 ай бұрын

What might blow your mind too are a type of sensor, found in most smartphones, smart watches, etc., which is closely related to MEMS microphones in their construction (and which in fact came first): MEMS barometers. Rather than the membrane being moved by sound, it’s got a sealed cavity so that as external air pressure changes, the air in the cavity expands or contracts, making the membrane bow in or out, changing its distance and thus the capacitance. What’s incredible is that they’re so sensitive that this is what your phone uses to detect changes in your altitude. Yes, your phone tells how many floors of stairs you climbed by measuring the difference in air pressure. So you might think it’s sensitive enough to measure a meter or two of altitude, right? Nope, they have a resolution of a few _centimeters._ I find it truly incredible that these sensors can actually tell the difference in air pressure over literally one palm’s width of altitude.

@heatshield

6 ай бұрын

@@tookitogo it’s truly awesome tech. I remember figuring out that one of my old android phones had a Yamaha component for an accelerometer. Been pretty hooked on micro tech since then.

It's amazing that even a crappy $10 pair of earbuds has this much engineering put into it.

@blakeramsey3373

6 ай бұрын

exatly what i was thinking, its probably pretty "plug and play" for the manufacturers but still so cool

@DudeWhoSaysDeez

6 ай бұрын

so much fabbed silicon in a cheap throwaway device

@unixux

6 ай бұрын

People don’t appreciate just how far we got

@fatcatzero

6 ай бұрын

Economy of scale is a crazy thing

@FATMAC2

6 ай бұрын

im amazed at the amount of reverse engineering lol

I'm always blown away by how intricate fab stuff can get! way cool investigation

@multiarray2320

6 ай бұрын

you alao got access to a SEM, right? maybe investigating something like that would be a nice video idea as well :)

The 3d model of the mic kind of blew my mind. I loooooooooooove seeing stuff under electron microscopes, thank you for making this. Fantastic all around.

Excellent explanation! Never realised there was so much complexity in there, it's certainly a lot more than just a tinier microphone!

Absolutely crazy that something like this is 2x inside a $10 headphone, so each maybe 10cents, at most. 300mm waver gives maybe 50'000, so a whole waver with bonding and everything for less than $5000. That "buzzer" most likely is the battery, btw.

@TheMrTape

4 ай бұрын

There's probably just a single mic in one of the earbuds. Lookup "digikey mems mic" and you can find them starting at 47 cents each if you buy 1000. This is a US retailer selling reputable parts. If you get them directly from China, which is probably where these earbuds originate, they'd of course be significantly cheaper.

Also not a seasoned audio engineer here but my trivial explanation for the cavity below the membrane is, that it provides a neutral pressure reference against the outside. Thus the microphone becomes omnidirectional. If it would be open from the back, sound waves coming from the side would not be picked up. Thank you for that brilliant deep dive of a video!

@UNSCPILOT

6 ай бұрын

huh, that's a concise but insightful bit of knowledge, and goes to explain quite a bit, thanks!

@BreakingTaps

6 ай бұрын

Neat, TIL! Thanks for the explanation!

@andynazay

6 ай бұрын

😊😊😊

@commander-tomalak

6 ай бұрын

To my best knowledge, the size of the cavity vs. the diameter of the central hole define your lower cut-off frequency, otherwise this thing would be driven into saturation by low-frequency or static pressure.

@spvillano

4 ай бұрын

@@commander-tomalak that's my thought. Vented microphone to control for VLF and barometric pressure, the cavity for resonance, the steps to tune and reflect various frequency harmonics. Impressive, given the frequencies used in narrowband telephony is around 300 - 3400 Hz, wavelengths ranging from around 45" - 4"! Yep, a quick lookup shows they're called a MEMS resonant microphone array. Here's a discussion on active noise cancellation using the technology. www.ncbi.nlm.nih.gov/pmc/articles/PMC7978172/

Wow, excellent presentation. The SEM images and CGI blend perfectly. What an amazing piece of technology. I wonder if the dimples in the top layer are for controlling the stiffness of the disk.

@jakubnevaril9768

6 ай бұрын

They would probably also help increase the capacity by enlarging the surface area when the membrane is close to the other electrode.

@victortitov1740

6 ай бұрын

i would speculate that it's mostly just a byproduct of how the thing is manufactured

@BreakingTaps

6 ай бұрын

Thanks! I believe the dimples are _mostly_ an artifact of the manufacturing steps to make one. There are a few ways it could have been made, but my current theory is: pattern and etch the base substrate giving nice clean holes, deposit a layer of glass on top (which will naturally form rounded dimples over the holes), deposit another layer of undoped polysilicon and then a doped polysilicon layer, then finally etch out the sacrificial glass layer (with HF or plasma) leaving the gap between the two layers. Finally flip and etch the big cavity. Just a guess but it makes sense to me. The holes in the lower layer are to help air move past it with minimal resistance, but the dimples on the surface aren't really needed. So I think it's leftover from the layered nature of fabrication.

@professordeb

6 ай бұрын

@@BreakingTaps You mean a totally flat disk without dimples could not be fabricated? I wouldn't expect that, but I don't know anything about processes at this micro level. I'm just blown away that they actually work as well as they do. Are neodymium magnets used at this scale?

@BreakingTaps

6 ай бұрын

​@@professordeb It's technically possible to get a flat disk on top of the hole'y layer, but it would be a lot more work. There's another process called "chemical-mechanical planarization" which is basically a super fancy sand paper for wafers 😁 It's used to flatten the top layer by grinding/polishing until all the ridges are gone. It's often used on high density microchips like computer CPUs, because you have soooo many layers that everything starts to get rounded. So they periodically flatten it with the planarization tools. So to get a flat surface for this device, you'd deposit a really thick sacrificial layer, then grind it back flat, then proceed with the next steps. But if you don't _need_ it to be flat, you can skip and save money. Magnets aren't used a lot at this scale because (I think) the magnetization process needs high temperatures and it can be difficult for the devices to survive. Although I've seen some papers about using laser-heating and such, so I'm sure it's doable. At this size, electrostatic, thermal and piezo mechanisms tend to be more common.

such an underrated channel I have so many other things to do today but your SEM experiments just have me glued, amazing stuff.

@spvillano

4 ай бұрын

I told Santa that I wanted an SEM for Christmas. Unfortunately, he said that I was too heavy, get the fuck off of his lap. Back during the last Ice Age and I was in school, our junior high and high school had donated TEM units, which we were allowed to use. By the time my kids went to school, the electron microscopes were long gone, as were the optical microscopes.

Dude, this is awesome to see so detailed and even broken open. And on top of that, as if that wasn't enough, you explain it all as well and even use super beautiful renders for that explanation!

Thank you for making these videos. They really help give perspective on this extremely tiny yet extremely impactful part of all our lives. Plus the SEM images and CGI you make are absolutely beautiful to look at.

I work at a very old 200mm semiconductor fab as an equipment engineer. One of my processes is polysilicon deposition through LPCVD. Hearing these terms in a video about mics in earbuds is awesome.

Man I am glad I found your channel. This stuff is awesome. TY

the way this microphone works is, there is a small hole that allows to equalize the pressure between the inside and outside of the chamber slowly later when pressure is applied to the top the fluctuations are relative to the mean pressure.

@spvillano

4 ай бұрын

The cavity is a resonant chamber. The microphone is referred to as a MEMS resonant microphone array. Pair them up and one can have quality active noise cancellation. The cavity is a resonant chamber, the steps for different frequencies.

Your animations are fantastic!

This is great! Hah, I just bought these ONN buds on sale for ~10$ and they work great as a basic hands/wires free headset. I was marveling at the amount of tech crammed into these cheap lil guys and you've revealed their innermost secrets :D Always enjoy your microscopy.

You just spoke about almost every topic I had in my master's degree lecture "Physical Sensors in Silicon Technology", we also had the etching process RIE (Plasma etching - Reactive ion etching) explained in details in there. Thank you for making this video, I just finished my university degree and it's cool to see some practical stuff for a change!

@spvillano

4 ай бұрын

The MEMS resonant microphone array is a fascinating technology, especially the tiny resonant chamber within the unit.

This was awesome - I will be subbing!

I love electron microscopes and pictures they produce. Really like to watch your content. I always learn something new. Thank you!

The amplifier for the microphone looks quite interesting too. Looks like too many parts to be purely an analog amplifier. I wonder if they're driving the microphone with AC and de-modulating to get the audio?

Nice work. This looks surprisingly easy to make.

Just insane the detail achieved and how simply such a complex topic has been conveyed. Your videos are incredible, among the best out there. 😮😮😮

Just one correction. The balls at the ends of the bond wires are tiny solder bumps and not Au balls. Solder bumping, wire bonding, die stacking and 3D packaging in general would make a great episode!

@maxenielsen

6 ай бұрын

Commonly, after making the bond to the lead frame (after first bonding to the bond pad on the chip) the wire-bond machine severs the wire with an electric arc. This arc produces a spherical blob of molten wire, which cools and solidifies. That little ball is right below the surface of the bonding foot. So when the bonding foot is pressed down onto the next bond pad on the chip, it compresses the ball onto the bond pad, creating the electrical and mechanical connection to the bond pad. So the little balls are of gold or aluminum, whatever the bond wire metal happens to be.

@maxenielsen

6 ай бұрын

Now, where chips are bonded directly to each other or PCB, the balls are usually made of solder or tin or indium. Actually, they are referred to as bumps for this kind of bonding operation.

Really cool video dude! I just hooked up a MEMS mic to my WLED display for music reactivity. Cool to see exactly how these little pieces of “fly sh!t” actually work! Merry Christmas!!!

Incredible video with stunning visual and intriguing explanation. Keep the good work.

The fact people figured out how to make this stuff!!! It’s insane to think about. We don’t give ourselves enough credit as a species.

I LOVE your videos. I learn so much. Thank you! 🙏

It’s just FASCINATING to say the least to not only come up with such solutions but make them at scale for dirt cheapp! That work sooo well! The amount of research, knowledge, experience, and creativity of these engineers is legendary

EXCELLENT! This has been a long time coming. Thank you!

This was so fascinating to watch! Thank you much. I just stumbled accros your channel and you got so much more videos :O

Absolutely fantastic as always! Man I wish I had and SEM to play with!

What a perfectly paced video, I couldn't stop watching it. Thank for you the impressive images and insightful analysis!

Intriguing stuff, keep em coming!

Really cool! Thanks for showing !!

This was on my feed since it was on KZread.. but was scrolling down.. but after seeing the reel had to watch the full video.. Absolutely amazing. The amount of tech that goes in inside 10 dollar microphone just blows my mind..

Amazing video ! Thanks a lot for all the time and effort.

Really enjoy all your videos mate, great work!

What a fascinating dive into cool microscopic engineering. Great video all round!

I look forward to these posts so much. It's the highlight of an otherwise rather mundate youtube experience for me.

incredible modeling and images, great explanations!

Superb tech and superb video! Thank you!

Sick, never knew how they fit microphones into those earbuds, thanks for showing!

I’d love to know more about the hole pattern. Most is a hexagonal fill which is good for maximum density and uniformity. Edges are concentric rings, and in between is a hybrid.

These microphones typically have a digital output using "pulse density modulation", where the rate of toggles encodes the analog signal value. The three ports coming off the control die are almost certainly power. ground, and audio out. Also +1 for DRIE video. That was the first thing I noticed when you cracked it open. The Bosch process is cool!

@spvillano

4 ай бұрын

I counted 7 heavy etchings on one component, couldn't get a good count for thinner etchings for things like the resonant chamber. Then, I considered how many ways I could badly injure myself on the equipment that builds these devices... Ion beam, HF, yeah, gotta be a pain to maintain those machines!

Your video quality blows me away

wait wait wait. How do they etch the giant hole and then make the membrane on top?? Do they come from the back?

thank you for creating and sharing this, that was amazing and enlightening

Dang your channel is the coolest!

This kind tech content is mesmerizing, I'm far from understanding how all this parts connect and talk to each other, but its exciting to see what can be done.

Amazing video and produced! thanks!

Always a pleasure to see a new video from you.

Oh wow this is amazing!! Thank you for making such a detailed video about it!

Your videos are amazing, thank you for them.

I absolutely love this channel

Interesting to see the ridges inside that microphone cavity. At first i thought they were there to help with echo and reflections, similar to how some speaker boxes deal with it. Now I'm wondering if the etching process is calibrated to make those ridges a certain size specifically for essentially tuning it.

Another incredible video! Thanks for the effort you put in

MEMS is the quiet revolution. That tiny microphone, tiny sensors, gryoscopes on drones and modern airplanes, all done with MEMS. It started as engineers seeing other applications for IC processes than just electronics and making such things as working microscopic motors, but then quickly advanced to more useful concerns.

Awesome! A new microscopy video!

Great video and images! If you have a fine diamond saw or pad, you might consider grinding off material from the side, instead of breaking it open. In that way you can make reasonably clean cross sections, especially with the use of some extra resin.

@BreakingTaps

6 ай бұрын

Will try that on the next one! I admit to being a bit lazy and just smashed it with some tweezers haha

Fascinating, great visualizations, thanks.

Ordinary ceramic capacitors can also respond to sound. I've seen speculation that this effect could be used to turn ordinary electronics into surveillance devices but I haven't seen a proof of concept yet.

The quality of these videos never ceases to amaze me :)

This video provides a shocking amount of detail. Very impressed!

Wow! Never seen this channel before. Subbed. Very cool

really cool! I appreciate the source links in the vid

My Pixel Buds came with a warning that they have a Class 1 laser inside. Any idea what that might be used for and are lasers of this size particularly interesting?

@defenestrated23

6 ай бұрын

Laser microphones are a thing, but I'd be shocked if that was the actual use case. Seems like a more complex and lower fidelity approach. A quick search suggests it's an IR laser to detect when the bud is in an ear.

I really needed a bit of marvel and wonderment today. Thank you!

eally really cool, informative and educational. Thank you so much!!! I loved all the angles and even the 3D model that i have now idea how you got it. You, are, amazing!

This has answered questions I didn't know I had 👏

Awesome video! Great work!

I would guess the large cavity behind the membrane matters for the microphone's frequency response: Most practical microphones don't want to react to slow changes in ambient air pressure, because those can easily be much bigger than typical sound pressure levels, and could blow out the membrane. This is what the small hole in the middle of the membrane is for, to let the pressure equalize on both sides of the membrane (equivalent to a high-pass filter). Of course, if the equalization is too fast, then it can also equalize out low-frequency sounds, which would impact the frequency response of the microphone. The speed of this equalization depends on the hole size and the volume behind the hole (similar to a Helmholtz resonator with an additional loss term), so the manufacturer will tune either the hole size or the volume behind the membrane to set this frequency to a sensible value - I think 1-2Hz are typical for typical electret microphones. I would guess, then, that the hole is already as small as feasible in this process, for some reason or another. Then it would make sense for the manufacturer to make the volume larger (requiring more etching steps) in order to improve the frequency response at low frequencies.

@foobargorch

6 ай бұрын

can you explain what's the additional loss term?

Im actually more amazed at the quality of this video than anything else.. and wow, SEMs have really improved over the last decade or so.

really amazing! thank you very much for all your great efforts! subbed! :)

a very interesting topic covered very very neatly! good job :)

Thank you for the video! very cool!

Great graphics! Good explanation!

Super-cool indeed. Thanks for putting this together. It was fantastic for an audio nerd such as myself.

Why there is such a big cavity: my guess is that it is simply to do with ease of manufacture. They first make all the structures on top, then flip it over and etch through from the backside. Importantly they also intentionally leave a controlled-size hole that allows internal pressure to equalize over a controlled time (e.g. if device takes a plane ride or happens to be put in a vacuum during further processing), not too slow but not too quickly that the device wouldn't be able to pick up bass. Given the tiny size of the cavity, it can't have anything to do with acoustic resonances.

@chasingcapsaicin

6 ай бұрын

Has everything to do with acoustic resonances, and there are much more ambitious ones in the public market.

Wow, that was a truly incredible video. I was especially surprised and delighted with the model and animation you created to explain how the device works. I know that in terms of the principle of operation it is quite a simple device, but the scale of miniaturization and the way you presented it make me want to show it to my wife, children and friends. I am really impressed with your channel - keep up the good work. Regards

Great video, earned a subscriber. Keep it up!

Crazy... Thank you!

Wow, great dedication making the video.

fantastic video, I just found yer channel and I'm already liking it

Why didn't I find this channel earlier. ❤ SEM's pictures are stunning

Fascinating as usual.

ooh, your blender animations are getting really good!

I guess the dimples would cause a nonlinear response to displacement? It's hard to tell what the neutral position is between the dimples and holes, but it looks like the dimples don't quite cross the holes. If I'm imagining this right, at low SPL/small deflections you'd get an initially sharp response as the dimple intrudes into the hole, and the changing size of the annular gap as the curve of the dimple passes the hole dominates the response. Once the straight(ish) part of the dimple enters the hole, the annular gap stops changing and the overall motion of the plate creates the response at higher SPLs. Pretty neat way to balance sensitivity and dynamic range if that's what they're doing.

I could watch videos of you looking at the microscopic details in technology and explaining them forever! :)

Now that was cool! Great video! First time I saw someone use a private electron microscope!

Gorgeous images!

Holy moly the presentation and info is so onpoint

Holy moly! That was intresting!

This is awesome, subbed

holy that was an epic video!

another banger, thanks bud ❤